[PlanetCCRMA] Re: Greetings FC2 I got capabilities and jack working

[Fernando Pablo Lopez-Lezcano]

> >> Yes, I guess that is because of the yamaha card. 
> >> 
> >> > With the command line:
> >> > /usr/bin/jackstart -d alsa -d hw -r 48000 -p 256 -n 3 -z &
> >> > I get a bunch of xruns:
> >> > **** alsa_pcm: xrun of at least 4.949 msecs 
> > [MUNCH]
> >> > **** alsa_pcm: xrun of at least 4.494 msecs
> >> > 
> >> > Is the command correct?
> >> 
> >> Well, you are not using the "-R", so you are not running with realtime
> >> priority (that is crucial to help avoid xruns). Could you try again with
> >> "-R"?
> 
> Ok, forgot about the -R option. Tried it and got less xruns but
> did get some with this command:
> /usr/bin/jackstart -R -d alsa -d hw -r 44100 -p 256 -n 3 &
> 
> Let me see if I understand, what is to be considered is the
> frecuency and number of xruns? The less the better?

Ideally you should get none. 

An xrun is signalled when the soundcard did not get samples to play in
time (or samples were not read in time if you are recording). For
playing back audio that means there will be a gap with silence and a
click for each xrun. Not good. 

Apparently things are even more complicated. Booting 2.4.26-1.ll in FC2
(the kernel built on FC1) I still get xruns. On the same machine, with
the same kernel but running in FC1 I get virtually no xruns. 

-- Fernando